1. Field of the Invention
This invention relates to a staged process for simultaneously converting coal to liquid hydrocarbon products and hydroconverting a heavy hydrocarbonaceous oil in the presence of a catalyst prepared in situ from small amounts of metals added to a mixture of oil and coal as oil soluble metal compounds.
2. Description of the Prior Art
Hydrorefining processes utilizing catalysts in admixture with a hydrocarbonaceous oil are well known. The term "hydrorefining" is intended herein to designate a catalytic treatment, in the presence of hydrogen, of a hydrocarbonaceous oil to upgrade the oil by eliminating or reducing the concentration of contaminants in the oil such as sulfur compounds, nitrogenous compounds, metal contaminants and/or to convert at least a portion of the heavy constituents of the oil, such as pentane-insoluble asphaltenes or coke precursors, to lower boiling hydrocarbon products and to reduce the Conradson carbon residue of the oil.
U.S. Pat. No. 3,161,585 discloses a hydrorefining process in which a petroleum oil chargestock containing a colloidally dispersed catalyst selected from the group consisting of metals of Group VB and VIB, an oxide of said metal or a sulfide of said metal is reacted with hydrogen at hydrorefining conditions. This patent teaches that the concentration of the dispersed catalyst, calculated as the elemental metal, in the oil chargestock is from about 0.1 weight percent to about 10 weight percent of the initial chargestock.
U.S. Pat. No. 3,331,769 discloses a hydrorefining process in which a metal component (Group VB, Group VIB, iron group metal) colloidally dispersed in a hydrocarbonaceous oil is reacted in contact with a fixed bed of a conventional supported hydrodesulfurization catalyst in the hydrorefining zone. The concentration of the dispersed metal component which is used in the hydrorefining stage in combination with the supported hydrodesulfurization catalyst ranges from 250 ppm to 2,500 ppm.
U.S. Pat. No. 3,657,111 discloses a process for hydrorefining an asphaltene-containing hydrocarbon chargestock which comprises dissolving in the chargestock a hydrocarbon-soluble oxovanadate salt and forming a colloidally dispersed catalytic vanadium sulfide in situ within the chargestock by reacting the resulting solution, at hydrorefining conditions with hydrogen and hydrogen sulfide.
It is also known to convert coal to liquid products by hydrogenation of coal which has been impregnated with an oil soluble metal naphthenate or by hydrogenation of coal in a liquid medium, such as an oil having a boiling range of 250.degree. to 325.degree. C., containing an oil soluble metal naphthenate, as shown in Bureau of Mines Bulletin No. 622, published 1965, entitled "Hydrogenation of Coal in the Batch Autoclave", pages 24 to 28. Concentrations as low as 0.01 percent metal naphthenate catalysts, calculated as the metal, were found to be effective for the conversion of coal.
In U.S. application Ser. No. 702,271 it has been proposed to convert simultaneously a heavy hydrocarbonaceous oil and coal in the presence of hydrogen and of a catalyst produced in the oil by the thermal decomposition of a minor amount of an oil soluble metal compound of Groups VB, VIB, VIIB, VIII and mixtures thereof of the Periodic Table of Elements. It has now been found that certain advantages result when the hydroconversion process is conducted in stages. The heavy hydrocarbonaceous oil with the catalyst or with the catalyst precursor is introduced into a first hydroconversion zone. The first hydroconversion zone effluent is passed to one or more subsequent hydroconversion stages. Coal is introduced into any of the hydroconversion stages except into the first stage. The staged process permits regulation of reaction time separately for the heavy oil and for the coal.
The term "hydroconversion" with reference to the oil is used herein to designate a catalytic process conducted in the presence of hydrogen in which at least a portion of the heavy constituents and coke precursors (as measured by Conradson carbon residue) of the hydrocarbonaceous oil are converted at least in part to lower boiling hydrocarbon products while simultaneously reducing the concentration of nitrogenous compounds, sulfur compounds and metallic contaminants.
The term "hydroconversion" with reference to coal is used herein to designate a catalytic conversion of coal to liquid hydrocarbons in the presence of hydrogen.